What is Catamenial Epilepsy?

Ovaries and testes produce sex hormones. Primarily, they control and maintain our reproductive systems and also have an influence on muscle mass, bone strength, emotions, or behavior. They also begin to influence brain function before birth. Since women have a monthly cycle, the hormonal changes are more obvious than in men.

Ovaries produce estrogen, progesterone, and testosterone in small amounts. Progesterone and estrogen promote the menstrual cycle changes. They also act on brain cells: estrogen excites them and can make seizures more likely to happen. In contrast, natural progesterone has an anticonvulsant effect and can inhibit or prevent seizures.

“Catamenial Epilepsy” is the term used when referring to seizure exacerbation in relation to the menstrual cycle. Usually women with catamenial epilepsy do not have seizures only associated with the cycle, but they have more during that time. Occasionally, women only have seizures predictably associated with the cycle. When seizures occur just before or during the onset of menstruation, it is thought to be triggered by the perimenstrual fall in serum progesterone levels. Seizures at the time of ovulation may be precipitated by the elevation of estrogen levels.

To help with the treatment of seizures, it is important for women to keep a calendar of their menstrual cycles, marking the days the patients have seizures and including other important aspects, such as missed medication, stress, intense physical training, illness and sleep deprivation.

Acetazolamide (Diamox), a carbonic anhydrase inhibitor that also has anticonvulsant properties, has been reported to reduce seizures in women with predictable catamenial seizures. Natural progesterone has also been useful in women with catamenial exacerbation due to the anticonvulsant effects.